Electric elevator



(No Model.)

' R. 0. SMITH.

ELECTRIC ELEVATOR.

Patented Man 15 1892.

Gimme o UNITED STATES PATENT" OFFicE.

RUDOLPH C. SMITH, OF YONKERS, NEIV YORK, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO THE NATIONAL COMPANY, OF CHICAGO, ILLINOIS.

ELECTRIC ELEVATOR.

SPECIFICATION forming part of Letters l atent No. 471,064, dated March 15, 1892. Application filed November 30, 1891- Serial No. 413,560. (No model.)

To all whom it may concern.-

Be it known that I, RUDOLPH 0, SMITH, a citizen of the United States, residing at Yonkers, in the county of Westchester and State of New York, have invented certain new and useful Improvements in Controlling Electric Elevators from the Car, of which the following is a specification.

My invention relates to electric elevators,

IO and more especially to means whereby an electric elevator may be readily and safely operated to run at varying speeds in connection with ordinary systems of distribution of electric current.

It is well known that in operating, electric elevators it is necessary to provide means whereby the speed of the elevator may be regulated so as to run properly under varying load and to be stopped and started without sudden jars or jolts and without danger of burning or otherwise injuring the electrical apparatus. It is also desirable to regulate the speed of the elevator for the purpose of inspection.

In order to effectually operate an electric elevator it is necessary to have a switch for controliin g the currentin stopping and starting and for reversing the current of the motor, and heretofore it has been customary in 0 practice to put the switch in some stationary position near the motor, although it has been proposed to place the controlling switch on the moving car. This, however, has been open to objections, for the reason that the circuit-wires leading from the motor to the traveling car are usually made flexible and inclosed in a flexible tube, and when the current of great quantity is passed through the motor and through these connecting-wires there is a liability of burning or injuring the conductors or of the insulation being impaired, which would result in short circuit. Furthermore, having a current of considerable quantity controlled bya switch-board on 4 5 the car, there is liable to be considerable sparking, which is annoying and perhaps dangerous to the passengers in the car.

One of the objects of my present invention is to overcome these objections and to provide means whereby the switch maybe mounted on the car and travel therewith and be operated without danger of sparking, burning, or otherwise interfering with the circuits. In order to accomplish this, I arrange the circuits so that only the wires leading to the field-magnets are connected positively with the switch device on the car, while the armature-circuit, over which a varying quantity current is passed according to the work to be done, is entirely independent of the car and the switch thereon.

In connection with this object of my invention I accomplish further results in the way of automatic regulation of the current through the armature, which will be more particularly pointed out hereinafter, as well as control the resistance of the field-magnet circuit in the manner hereinafter set forth.

In order that my invention may be more clearly understood, reference is made to the accompanying drawing, in which I have shown diagrammatically one embodiment of my invention, sufficient to explain the principles thereof and enable those skilled in the art to readily apply it in practice.

In the drawing, A represents the ordinary winding-drum, around which passes the elevating-rope B, which is attached to the car B, passing over the suitable sheaves B in the usual manner.

Mounted on the car B is a switch device S, the circuits leading therefrom being, as usual, inclosed in a flexible tubing, so that the connection will be properly maintained as the car moves up and down. This switch device may be of any suitable construction; but I have shown the preferred form, which consists, essentially, of a pivoted arm S, mounted to be operated by any suitable device, as a crank or handle 3, and so arranged that in 0 its normal position no current passes through the switch. Arranged on. either side of this switch-arm is a series of contacts suitably connected, so that the direction of the current through the switch will be controlled by 5 moving the switch-arm either to the right or to the left in a manner well understood. As

before stated, the circuits of the motor and switch are so arranged that only the current which passes through the field of the motor is lead to the switch device, the current passing through the armature being either mechanically or preferably automatically controlled on'moving the switch controlling the circuit through the field.

To more particularly describe the circuits, let 1 represent the plus binding-post, which is connected with the feeding-wire of any ordinary system of distribution. From this post a wire 2 leads to the pivot-point of a switch m, which is properly insulated and the handle m of which is connected electrically with the solenoid b, from whence the current passes by the conductor 3 to the plate or sector 4: of the switch. Arranged around this sector and the corresponding sector 5 of the opposite side of theswitch is a series of contact-blocks 7 8 9, the blocks being connected by suitable resistances 10 and 11. These contact-blocks on either side of the switch-arm are suitably connected, so that the resistances will be properly included in the circuit, regardless of which way it is moved, only the direction through the resistances will be varied. The arrangement is such that when the switch-arm is moved to the right or to the left over the first contactblock no resistance is in the circuit; but as it reaches the second contact-block a resistance of a predetermined amount is included in the circuit, and so on to the other contact-blocks, there being as many as may be desired, according to the specific requirement of any particular case, it being understood that as the switch is moved farther from its normal position more resistance is included in the circuit at each contact-block as the arm is moved to the right or the left to change the direction of the current. For instance, assuming the switch-arm S to be moved onto the contact 7, the conducting portion of the switch-arm will complete the circuit between the sector l and the contact-plate 7 and thence it willpass by the wire 12 directly to the fieldmagnet coils f of the motor, and then by the wire 13 back to the sector-plate 14, and by the conducting portion 8' of the switch-arm to the sector 5, and by the conductor 15 to the minus binding-post 16. It will thus be seen that as soon as the switch-arm S is moved the circuit of the field-magnet is completed and the full current passes through the field, and this is supposed to be a current having a uniform voltage. WVhen, however, the switch is moved to the contact 8, the resistance 10 is included in the field-magnet circuit and the currentthrough the field-coils of the motor is reduced, and so 011 through the other resistance devices at the switch.

The switch m controls the armature-circuit of the motor, and the armm' of the switch is preferably weighted, as at m or provided with a spring m or possibly both, which has a tendency to maintain the switch m open. When, however, the circuit is completed by the switch on the car, the coils of the solenoid b are energized, and this solenoid operates to close the switch on and complete the armature-circuit. From the switch m passes a conductor 17, leading to a solenoid c, from whence it passes to the brush g of the armature h, through the coils thereof to the brush g, and in the present instance to the coil of the solenoid i and to the brush j of the safety-resistance device, and thence to the binding-post 16. It is to be remarked that the current through the armature is always maintained in the same direction, the motor being reversed by reversing the current through the field-magnet coils.

The solenoid c is arranged to operate a brake device for stopping and holding the motor, which is diagrammatically indicated in the drawing, in which cl represents a lever pivotally mounted at d and provided with a suitable weight or spring (1 which normally holds the brake against some moving part of the motor or its connected mech- I anism-as, for instance, the armature-shaft. When, however, the coils of the solenoid c are energized bythecurrent passingtherethrough, the core of the solenoid is raised, releasing the brake device and maintaining it out of operative position as long as the current flows through the armature-circuitin proper quantities.

hile I prefer to use the solenoid c, the brake device can be mechanically connected to the switch-arm to be operated by the solenoid b, as indicated by the dotted lines, and the spring or Weight attached to said switch at would operate to apply the brake as soon as the current is cut off.

The safety-resistance device is arranged in the armature-circuit, and its brush j is normally in position to include this resistance in the armature-circuit, and in order to insure this normal position of the brush j I provide mechanical means, which in the present instance are shown as being operated by the brake-lever d. Thus I have shown a lever 6 preferably provided with a weight e, which will normally rest upon the brake-lever d; or in preference to this it maybe a mechanical connection and further provided With a bifurcated end e arranged to operatethe brush j. This brush j is provided with means which tend normally to move it to a position to cut out the resistance k,and I have shown a level; Z, having a weight or spring Z, which will move the brush when free to cut out the resistance 70. To further control this, however, I provide the solenoid t', the coils of which are so arranged that its core t" is also connected to the brush j and controls its movement.

Such being the preferred arrangement of the device, I will now proceed to describe its mode of operation. The switch-arm S is shown in full lines in its normal position with no current through the field; but for convenience of explanation the circuit through the armature is shown completed, it being supposed that the switch-arm S is moved to one or the other of the contacts, it being indicated in dotted lines as bearing on contact 9. As soon as the circuit is completed at the switch between the segment 4 and contact? the field is energized with the full current from the line and the solenoidb is also energized,instantly closing the switch m of the armature-circuit. This closing of the armature-circuit will release the brake device by the mechanical connections shown in dotted lines or by energizing the coils of the solenoid c, and the brake will be moved away from its bearingsurface. The lever 6, either by its mechanical connections or the weight 6, will be tilted to raise its bifurcated end a in a manner to release the brush 7' and allow it to be operated by its weighted lever Z to cut out the safetyresistance if it were not otherwise controlled. The current of the solenoid '1', however, under these conditions is sufficiently strong with the safety-resistance ]t' in the circuit to hold the brush with its weighted lever at the point indicated to include said resistance, and the motor starts under a limited quantity of current. As soon, however, as the armature commences to rotate, producing counter electro-motive force, the strength of the current passing through the coils of the solenoid t' is decreased and the weighted lever 1 operates to move the brush to cut out more or less of the safety-resistance coils in, and when the armature attains its normal speed the adjustments are such that the whole of the safety-resistance is supposed to be cut out. If, however, the current through the ar mature is increased above its normal, the solenoid i will operate to cut in more or less of the safety-resistance, and it thus becomes a safety device to regulate the quantity of current and prevent injury to the motor. Vhen the motor is to be stopped, the switch-arm S is moved to its normal position, breaking the circuit through the field-magnet coils of the motor and of course releasing the switch-arm m, which is immediately operated to break the circuit of the armature by the weight or spring. At the same time the brake-lever d is operated to apply the brake to the motor by its weight or spring, and this in turn operates the lever c, causing its bifurcated portion 6 to mechanically draw the brush j to the position shown in the drawing, where it is held as long as the brake is applied, the safety-resistance 7t being in the circuit, and thus the parts remain until the field-magnet circuit is again closed. Of course it will be understood that if the switch-arm were moved to the right instead of to the left, as shown in the dotted lines, the same operations would occur, the only difference being that the current through the field-magnet coils would be in a reverse direction, causing the motor to rot-ate accordingly.

It is well known that a motor runs slower when the field is fully saturated (other things being equal) than when a less current is flowing through the coils of the field, and in order to increase the speed of the motor under the conditions shown in the drawing I provide means controlled by the switch in the car, whereby the current flowing through the field-magnet coils can be varied. Thus it will be seen in the arrangement described that when the switch-arm S is moved to the first contact, right or left, the full current from the main line passes through the fieldmagnet coils in one or the other direction and the motor is started. Vhen, however, the switch-arm passes to the next or other succeeding contact of the switch, more or less of the resistance-coils 10 11 are included in the field-magnet circuit, and as a consequence less current flows through the coils of the fieldmagnet and the speed of the motor will be increased.

IVhile I have thus described and illustrated the preferred embodiment of my invention, it is evident to those skilled in the art that the principles thereof may be applied in various ways to suit the exigencies of any particular case, and I do not, therefore, limit myself to the precise construction and arrangement of parts set forth.

In some instances I arrange to operate the switch m, controlling the armature-circuit, from the car, and I have indicated in dotted lines an ordinary traveling rope 9', connected to the car and the switch on and adapted to be operated in the car by the lever r in a manner well understood.

It is evident that by the use of this invention I provide a practical way of utilizing a controlling-switch for the motor when mounted on the car and avoid the danger of passing the armature-current through the switch and its connecting wires, it being understood that there is little variation in the strength of the current of the field-magnet coils, the amperage of which is always low-for instance, in some conditions not more than one ampereand when the resistance is included, of course, even this amperage is reduced, the potential remaining the same, while in the armaturecircuits a relatively considerable amperage is used, according to the work to be done, and the dangers of passing this quantity of current through the switch and its connections are avoided.

lVhat I claim is 1. In an electric elevator, the combination, with the motor and car operated thereby and a switch located on the car, of circuit connections between the field-magnet coils of the motor only and the switch on the car, substantially as described.

2. In an electric elevator, the combination, with the motor connected to operate the car, of aswitch mounted on the car, the field-magnet coils of the motor being connected to the switch and controlled thereby, and means for automatically controlling the armature-circuit, substantially as described.

3. In an electric elevator, the combination, with the motor and car operated thereby, of field-magnet ci 1"- a switch carried by the car,

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cuits leading from the motor to the switch on the car, and the armature-circuit of the motor separate from the switch on the car, substantially as described.

4. In an electric elevator, the combination, with the motor and car operated thereby, of a switch mounted on and traveling with the car, circuit connections between the field-magnet coils of the motor and the car, and means, substantially as described, outside of said switch for controlling the armature-circuit, as and for the purpose set forth.

5. In an electric elevator, the combination, with the motor and car operated thereby, of a switch traveling with the car, circuit connections between the field-magnet coils of the motor and the switch, and armature connections controlled by said fieldqnagnet circuit, substantially as described.

6. In an electric elevator, the combination, with the motor and car operated thereby, of

a switch mounted on the car, the field-magnet coils of which motor are connected to the traveling switch, a switch in the armaturecircuit, and a magnet in the field-magnet circuit controlling the circuit of the armature of the motor, substantially as described.

7. In an electric elevator, the combination, with the motor and car operated thereby, of a switch mounted on the car, connections between the switch and the field-magnet coils of the motor, a switch controlling the armature-circuit and controlled by the field-magnet circuit, and an automatic brake device also controlled by the field-magnet circuit, substantially as described.

8. In an electric elevator, the combination, with the motor and car operated thereby, ot a switch on the car controlling the field-magnet coils of the motor, a switchcontrolling the armature-circuitof the motor, a brake for the motor, a safetyresistance device, and connections between the safety-resistance device and the brake, whereby the brake is applied and the safety-resistance is positively included in the circuit of the armature, substantially as described. I

9. In an electric elevator, the combination, with the motor and car operated thereby, of an automatic safety-resistance in the armature-circuit, a brake for the motor, and connections between the safety-resistance and brake for controlling said resistance, substantial] y as described.

10. In an electric elevator, the combination, with the motor, of an armature-circuit including a safety-resistance, a brake for the motor, connections between the safety-resistance and brake, and a solenoid also in the armature circuit for controlling the safety-resistance, substantially as described.

11. In an electric elevator, the combination, with the motor and car operated thereby, of an armature-circuit, a brake for the motor, a solenoid in the armature-circuit controlling the brake, a safety-resistance in the armature-circuit, connections with the brake for operating the safety-resistance, and a solenoid in the armature-circuit controlling the operations of the safety-resistance,substantially as described.

12. In an electric elevator, the combination, with the motor and car operated thereby, of a switch mounted on thecar, connections between the field-magnet-coils and the switch, an armature-circuit, means in the circuit of the field-magnet coils for controlling the armat ore-circuit, a brake and safety-resistance, and means in the armature-circuit for controlling said brake and safety-resistance, substantially as described.

13. In an electric elevator, the combination, with the motor and car operated thereby, of a switch device mounted on the car, connections between'the field-magnet coils only and the switch device, and resistances in said switch device on the car arranged to be included in the circuit of said field-magnet coils, substantially as described.

14:. In an electric elevator, the combination, with the motor and car operated thereby, of a switch device mounted on the car, and connections with the field-magnet coils of the motor, the switch being provided with contact resistance devices, arranged substantially as described, so that when the circuit is closed the full current passes through the field-magnet coils and when the switch is moved farther the resistance is included in the fieldmagnet circuit to increase the speed of the motor, as and for the purpose set forth.

15. In an electric elevator, thecombination, with the motor and car operated thereby, of a switch mounted on the car, a circuit between the switch and field-magnet coils, a solenoid in said circuit, a switch operated thereby and controlling'the armature-circuit, and resistance devices on the switch arranged to be included in the field-magnet coils to vary the speed of the motor, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of vtwo subscribing witnesses. 

